How Do You Know If Someone's An Otaku?

Over five hundred individuals in Japan were polled by the Mobile Marketing Data Labo, providing these insights into how folks can spot otaku:

1. They are using otaku slang, net jargon or 2ch chat
2. They just happen to have anime/manga/game goods about them
3. They respond to otaku type keywords and issues
4. They become very intense when the conversation turns to anime/manga/games, and only then
5. The tunes they hum are all anime related
6. They know excessive amounts about a given anime/manga/game
7. You can somehow just tell intuitively that they are an otaku
8. They talk unconcernedly about anime, manga and games all the time as if it were normal
9. They start talking about a seiyuu (voice actors)
10. They are carrying a bag from an otaku shop like Animate or Tora no Ana